In a POS terminal (Point of sale Terminal) or the like, an expendable item to be used is determined beforehand, printing is performed by a printer unit in the POS terminal using the expendable item, and a check of the quality of the printing is performed. The quality check is performed by visually recognizing a printed barcode or the like or processing the barcode or the like with a verifier and reading a numerical value of the barcode. A maintenance person adjusts printing density and a head position to be optimum when necessary. In this way, setting adjustment ranges are provided in the printer unit to improve versatility for the expendable item.
The quality check is based on the premise that an assumed expendable item is used. However, because of the convenience of a user who uses the POS terminal, the assumed expendable item is sometimes not used during operation. Further, because of a reason that printing content is clearer when a denser image is formed, the printing content is set to be dense more than necessary. Depending on setting conditions, the life of the printer unit is reduced.